The present invention relates to an apparatus for operating a machine having electric axes, in particular a processing machine, which executes courses of motion that have a functional relationship, and to a method for operating this apparatus.
From the prior art, digital multiaxial controllers for controlling real-time events, in particular courses of motion with a functional relationship, are known. German published patent application DE 197 239 56 A1, for instance, shows a digital multiaxial controller for controlling real-time events. The multiaxial controller includes a plurality of noncentral entities (CPUs), which can be synchronized to a central entity (central CPU) by means of a programmable clock signal.
The control is implemented such that each noncentral entity (CPU 2 through CPU n) is assigned its own electrical drive (A2 through An). Both central and noncentral entities each have an associated clock generator (Q1 through Qn) with which an operating clock pulse is generated. From the central entity CPU a, which can for instance be a numerical controller, a clock line leads to each noncentral entity. By way of this clock pulse, the corresponding noncentral entities can be synchronized to the central entity. In addition, all the distances communicate with one another by means of a bus system.
Drive and control applications that comprise multiple axes, such as machine tools, are equipped with such multiaxial controls. The embodiment described above, from the reference cited, has the disadvantage of highly complex wiring for clock lines and bus lines between the noncentral entities and the central entity, which can increase the risk of failure from run time and wiring errors, and thus can impair the operating safety. Moreover, the greater complexity of the wiring entails additional costs, since as a rule the wiring has to be done on-site by a technician. The transmissible quantities of data are limited on account of the field bus transmission and with increasing length of the lines, and idle time optimization options are also limited because of the existing lines. All in all, the embodiment shown in DE 197 239 56 A1 is a very complex approach, which leads to increased costs for machine maintenance and manufacture.